Pinnacle NTSB Update

[ultrarunner]

I would have to agree wiht BluDevAv8r. Heck, how the heck many "big iron' EXPERIENCED airline pilots screwed up...

MD-88 T/O attempt without the wing configured correctly... DFW I think?

NWA DC-9 take off attempt (same problem as above) DFW

USAir TRW in CLT

USAir LGA T/O attempt w/ rudder trim maxed to one side.

Heck, those are just the most blatent ones that come to mind, and I'm not that smart.

It 'aint always about an inexperienced crew, or inexperienced pairing.

 

[TIS]

Pressurization shouldn't be an issue the cabin bleeds down very slowly, less than a couple hundred feet per minute (see above explanation). If you do get a CABIN ALT message procedure is O2 masks - don 100% flow, crew communication establish.

If I may suggest, please try going up to FL410 and have a dual flameout next time you're in the sim. I bet you'll have more than a couple of hundred feet per minute of cabin ROC. Even of you don't, it still begs the question do you really want to be gliding around forever waiting for the cabin to come up to you when you can get on down to thicker air and get an engine running again?

I might agree that in something like a 767 with such a huge pressure vessel you might see very little cabin altitude change in a dual flameout, but in a tube like an RJ, that air is gonna go out fast (by comparison). Add to that the positively whooped nature of door and exit seals and not to mention sticky outflow valves on the typical commuter airliner, and it seems to me that counting on a serious problem when your inflow air quits is safer than assuming that the leakdown will be slow and easily dealt with.

As I said, I'm not a CRJ pilot but I don't have to be to know that when half the pressurization equation is removed from the picture, it places a time limit on the solution you choose to apply to your problems. In my mind, getting to 300 Kts to attempt an airstart whould have been the very highest priority job to get done. That didn't happen and as a result, there was NEVER any realistic possibility that the engines would ever run again. Waiting until 13,000' to do an APU assisted start is cutting those margins pretty thin.

Whatever we agree or disagree on, we seem to share one belief - that this accident will highlight the serious gaps between what the pilots of these aircraft are taught and what they need to know when the chips are down.

TIS

 

[BID]

This is a pretty long thread and I have not gone through it all. It seems it has gone in the direction of mistakes made by regional airline pilots vs. major airline and if that is the case I feel it is disrespectful to the deceased pilots.

I do know the QRH to restart the engines is poorly written for the CL-65. I am not sure if this has been mentioned before, and if it has I apologize for bringing it up again, but if you do not match the 10th stage switches with the "closed" indication, you are not going to get air to the engines to start them. It has nothing to do with the valve position, but with the switch position. (APU LCV interlock protection) I did not think about this until I went through the QRH the other day and I remembered my sim instructor stressing the importance of pushing both 10th stage switches in to match the closed light indication. This mistake could easily have been made, especially under such a stressful situation. In the end, this is just speculation. The facts I am sure will come out, but I think it is worth to mention for new CRJ drivers. Once again, I apologize if this has been mentioned before and if I am wrong, please someone correct me.

I want to be respectful to the crewmembers that perished during this accident. I am a firm believer that something like this can happen to anyone, regardless of your "top gun" jet experience. We do not know all the facts and once they come in we can hopefully learn from them.

B

 

[Rez O. Lewshun]

That's why Pitch mode is the safest and sometimes most accurate mode to climb in. If for some reason its forgotten, it will just level off and maybe start descending once the wings get tired...

Pitch mode is direct control of Angle of Attack which is in the words of the FAA 'the essence of aircraft control'

God Bless.....

 

[Diesel]

I'm agreeing with G200. Holy crap I just said that.

We go to 450 in the plane I'm in all the time. Probably 5 or 6 times a week. It's not a race to the top. Take your time and get there slowly.

We have to climb in vs mode because the **CENSORED****CENSORED****CENSORED****CENSORED** thing occilates so bad it makes you want to throw up.

A lot of times going through 310 I set a 1000' fpm climb rate. Something nice and steady so that ATC can expect that from you all the way up.

This also gives you a little airspeed cushion that you will need to get over the hump at 430 or 450.

Take your time go slow and sometimes accept the fact that you are only going to climb at 300' fpm to the top of the hill.

If the plane won't do it don't push it. It's just not going to work out burn some fuel and then go to the higher alt.

VS is not the devil everyone says it is. PAY ATTENTION to it. Watch your airspeed and don't rely on your AOA. Some aren't even certified over 290.

 

[efiscompmon]

THAT PICTURE ISN'T ME. JUST SOME HIGH SCHOOL DROP OUT.

Actually, I am pretty sure I saw it under the heading "LAST SEEN WITH:" on an Amber Alert last month....

 

[patq1]

Pitch mode is direct control of Angle of Attack which is in the words of the FAA 'the essence of aircraft control'

God Bless.....

Please explain that to me. I believe that Pitch mode controls the pitch attitude(angle) not the angle of attack.

pat

 

[Diesel]

Holy crap EFIS that made me laugh my ass off. I'm going to have to change my signature.

 

[efiscompmon]

May I suggest "Chester D. Molester, Former parish priest, now a successful Cub Scout Troop leader"

Actually, he looks like an inspector at the BHM FSDO....coincidence? I think not.

 

[Rez O. Lewshun]

Please explain that to me. I believe that Pitch mode controls the pitch attitude(angle) not the angle of attack.

pat

If pilots can't control AOA, we're in big trouble (in general, NOT to this specific thread title). If the critical AOA was exceeded, how would it be reduced? Pitch control, either with yoke movement or autoflight, which is PTCH

When you use PTCH mode in the CRJ, (I know no other jet) you are setting a specific AOA. This AOA is maintained all the up to the max weight altitude the aircraft can maintain. In addition, this AOA is less than critical so the aircraft will never stall. It may stop climbing, or even settle (decend) but the wing won't stall. That is the beauty of it. Set the PTCH or AOA and work on your monthly bid....

CRJ training types don't advocate PTCH mode much because it is related to ROLL mode which is really not a good default mode to be in... but PTCH is different, because....it controls AOA...

Pilots always control AOA but it is difficult and costly to install accurate AOA indicators and use them. If we did have AOA indicators we wouldn't have to set speeds for different weights and we could fly L/Dmax... But we don't, so we really don't think in terms of AOA...

I recall the L-1011 had an AOA indicator....

Anybody with better knowledge or corrections pls chime in.....

Donate to the Fund.....God Bless.....

 

[Rogue5]

When you use PTCH mode in the CRJ, (I know no other jet) you are setting a specific AOA.

Um, well... Whipping out the old CRJ 200 PRM on page 2-25 it says "Pitch mode will maintain pitch angle sensed at the time of autopilot engagement." Pitch angle, in other words attitude referenced to the horizon, not Angle of Attack, or attitude referenced to the relative wind. This is why when climbing in PTCH mode in any kind of wave activity airspeed will increase or decrease while attitude (say 5 degrees) will be maintained. Climb up too high in a constant pitch, airspeed will decrease as angle of attack increases and you will stall the wing.

Going back to my "Aerodynamics fro Naval Aviators" knowledge I remember it being hammered home that you climb due to excess thrust, not lift. So if you have the excess thrust to push you higher, and fix an attitude referenced to the horizon, you can be pushed high enough to exceed the critical angle of attack.

Think "Power-on" or "departure" stall: Full power, fixed pitch attitude to the horizon. Airspeed decreases, AOA increases to beyond the critical, you're now looking at the ground...

 

[patq1]

If pilots can't control AOA, we're in big trouble (in general, NOT to this specific thread title). If the critical AOA was exceeded, how would it be reduced? Pitch control, either with yoke movement or autoflight, which is PTCH

When you use PTCH mode in the CRJ, (I know no other jet) you are setting a specific AOA. This AOA is maintained all the up to the max weight altitude the aircraft can maintain. In addition, this AOA is less than critical so the aircraft will never stall. It may stop climbing, or even settle (decend) but the wing won't stall. That is the beauty of it. Set the PTCH or AOA and work on your monthly bid....

CRJ training types don't advocate PTCH mode much because it is related to ROLL mode which is really not a good default mode to be in... but PTCH is different, because....it controls AOA...

Pilots always control AOA but it is difficult and costly to install accurate AOA indicators and use them. If we did have AOA indicators we wouldn't have to set speeds for different weights and we could fly L/Dmax... But we don't, so we really don't think in terms of AOA...

I recall the L-1011 had an AOA indicator....

Anybody with better knowledge or corrections pls chime in.....

Donate to the Fund.....God Bless.....

In the airplanes I've flown, pitch mode does exactly what it sounds like. It controls the pitch attitude(angle) not the angle of attack. Once you set it, it will maintain that angle regardless of what the angle of attack is. For a refresher on the relationship between pitch attitude and angle of attack I suggest Stick and Rudder. I doubt the CRJ pitch mode is any different but since I don't fly one, I'm sure you know it better than I do. Hopefully you or someone else who does fly it can help me out with a reference to prove me right or wrong.

pat

 

[patq1]

Um, well... Whipping out the old CRJ 200 PRM on page 2-25 it says "Pitch mode will maintain pitch angle sensed at the time of autopilot engagement." Pitch angle, in other words attitude referenced to the horizon, not Angle of Attack, or attitude referenced to the relative wind. This is why when climbing in PTCH mode in any kind of wave activity airspeed will increase or decrease while attitude (say 5 degrees) will be maintained. Climb up too high in a constant pitch, airspeed will decrease as angle of attack increases and you will stall the wing.

Going back to my "Aerodynamics fro Naval Avaitors" knowledge I remember it being hammered home that you climb due to excess thrust, not lift. So if you have the excess thrust to push you higher, and fix an attitude referenced to the horizon, you can be pushed high enough to exceed the critical angle of attack.

Think "Power-on" or "departure" stall: Full power, fixed pitch attitude to the horizon. Airspeed decreases, AOA increases to beyond the critical, you're now looking at the ground...

Thank you,

Pat

 

[chperplt]

Sure sounds like a lot of people need to be rasing their hands during recurrent and asking a LOT of questions....

 

[Rogue5]

As for the airplane just levelling off in PTCH mode and not stalling, think of this:

Calm, cool day, taking off empty with minimal fuel. Rotate, pitch up, and clean up. How many degrees do you think it could hold in a climb? Say 15 degrees pitch attitude (conservatively). "Auto on" and push the PTCH button.

Now if you think that the aircraft will just climb until it is unable and then level off while maintaining that pitch, you are attempting to claim that this swept wing, or any aircraft for that matter, will now be able to maintain in level flight with that 15 degrees pitch attitude. No way.